R help - Dec 2008 - help with predict in stats4

Hi,

We're using stats4 for a logistic regression.  The code is

chdreg.logit2 <- glm(chd ~ age + sex, family = binomial)
summary(chdreg.logit2)
oddsratios <- coef(chdreg.logit2)
exp(oddsratios)

# Calculate model predicted values
pred <- predict(chdreg.logit2,type="response")

The glm part runs fine, and up to now so has the predict function.  
However, now we're getting the following error

Error in function (classes, fdef, mtable)  :
  unable to find an inherited method for function "predict", for 
signature "glm"

Any thoughts about why this seems to now be appearing. 

Thanks in advance.


-- 
======================================================================David
Kaplan, Ph.D.
Professor
Department of Educational Psychology
University of Wisconsin - Madison
Educational Sciences, Room, 1061
1025 W. Johnson Street
Madison, WI 53706

email: dkaplan at education.wisc.edu
homepage:
http://www.education.wisc.edu/edpsych/default.aspx?content=kaplan.html
Phone: 608-262-0836

David Kaplan wrote:
> Hi,
> 
> We're using stats4 for a logistic regression.  The code is
> 
> chdreg.logit2 <- glm(chd ~ age + sex, family = binomial)
> summary(chdreg.logit2)
> oddsratios <- coef(chdreg.logit2)
> exp(oddsratios)
> 
> # Calculate model predicted values
> pred <- predict(chdreg.logit2,type="response")
> 
> The glm part runs fine, and up to now so has the predict function.  
> However, now we're getting the following error
> 
> Error in function (classes, fdef, mtable)  :
>  unable to find an inherited method for function "predict", for 
> signature "glm"
> 
> Any thoughts about why this seems to now be appearing.
> Thanks in advance.
> 
> 
Just a guess, but perhaps you've loaded some other package which 
redefines predict() in an incompatible way?

-- 
Gad Abraham
Dept. CSSE and NICTA
The University of Melbourne
Parkville 3010, Victoria, Australia
email: gabraham at csse.unimelb.edu.au
web: http://www.csse.unimelb.edu.au/~gabraham